package com.kaesar.algorithm4.exercise.chp1;

import com.kaesar.algorithm4.base.edu.princeton.cs.algs4.Bag;
import com.kaesar.algorithm4.base.edu.princeton.cs.algs4.StdIn;
import com.kaesar.algorithm4.base.edu.princeton.cs.algs4.StdOut;

public class Stats {
  public static void main(String[] args) {
    Bag<Double> numbers = new Bag<Double>();
    while (!StdIn.isEmpty()) {
      numbers.add(StdIn.readDouble());
    }
    int N = numbers.size();
    double sum = 0.0;
    for (double x : numbers) {
      sum += x;
    }
    double mean = sum / N;

    sum = 0.0;
    for (double x : numbers) {
      sum += (x - mean) * (x - mean);
    }
    double std = Math.sqrt(sum / (N - 1));

    StdOut.printf("Mean: %.2f\n", mean);
    StdOut.printf("Std dev:%.2f\n", std);
  }
}
